Hi sboyd, if you purchase individual licenses, you'd need a license for each person using the software. If someone is using VueMinder on your centralized computer, a license would be needed there as well.
Since it sounds like you might have up to 35 users, there's a site license option which can cover all the users in your office and is more affordable than purchasing individual user licenses (and easier to manage, since it's not tied to individual user accounts). If some users work from home or remotely, they could still use the site license as long as they are able to connect to your network.
You can find more information about the site licensing options here:
http://www.vueminder.com/Buy.aspxMySQL Server can run on a cloud computer, web server, etc. It's not limited to a local network. VueMinder will be able to connect long as you have an static IP address for the server or a resolved DNS name, and the server is configured to allow TCP traffic on port 3306.
Please let me know if you have any other questions.